The word was recorded in English by 1640, from Greek, by way of Latin. Edward Reynolds, later Bishop of Norwich, used it to describe a phrase from the Roman philosopher Seneca, 'we live by dying'.
Latin scholars are believed to have built the word from two Greek words with opposite meanings, though for centuries it passed as ancient Greek. It has not been found in any surviving text from ancient Greece.
Behind the word lay two Greek parts, one meaning 'sharp, or pointed', the other meaning 'foolish, or stupid'. The first traces to a Proto-Indo-European root, *ak-, found in Latin acer and acutus, and Sanskrit acri- and acani-. The second has no confirmed root beyond Greek.
EAGER and VINEGAR share the same root and are related to each other. EAGER entered English in the late thirteenth century, from a French word meaning 'sour'. VINEGAR entered English around the same time, meaning 'sour wine'.
By the start of the twentieth century the word had loosened from the name of one figure of speech into the everyday sense it has now. In 1993, The Guardian used it to describe affordable caviar.
